Conventional continuous-time delta-sigma analog-to-digital converters typically include an analog loop filter applied to an analog input signal and a low-resolution clocked quantizer that provides a digital output therefrom. The output from the quantizer is input to a digital-to-analog converter (DAC), wherein the quantized signal from the quantizer is converted to an analog domain signal and fed back to the loop filter. The quantizer may be replaced with a quantizer based on a voltage-controlled oscillator (VCO), which leverages the phase of the VCO. However, using a VCO-based quantizer instead of a conventional quantizer may affect the performance and accuracy of the DAC. A typical conventional VCO phase quantizer includes a multi-stage multi-phase VCO connected to a multi-stage phase quantizer. The multi-stage phase quantizer determines the phase of the VCO by comparing the phases of the VCO for a particular sample to a reference phase; it then generates a quantized phase difference value. However, a conventional VCO quantizer may also produce output nonlinearities that can affect the performance and accuracy of the DAC. Therefore, it is important that the multi-phase oscillator is highly linear.